I think you're asking how to keep it clean, how to be proactive rather than letting it accumulate with road grime and stuff.

I wipe down the bike after each ride. 2 gallon bucket from Home Depot with detergent and cold water. While doing the wipe down, I put my sweat drenched jersey in the soapy water. This keeps the jersey from getting stinky. If the down tube and seat tube are covered with mud or grit, then I'm careful not to scratch up the paint. The wheels and spokes I do less frequent and when done, I use a separate rag. I rinse the rag often wih the garden hose during the wipe downs.

As a final step, I use a car spray finish like Mother's or Meguiars. Keeps it shiny and slick.

If you do the wipe down often, your bike will always look good and the paint job will last longer.